A prefabricated member for cast-in-situ combined channel and a construction method thereof

Abstract

The application discloses an assembled channel prefabricated component and a construction method thereof, and relates to the field of agricultural water conservancy projects. The prefabricated component comprises a plurality of oppositely arranged L-shaped prefabricated vertical plates and a cast-in-place bottom plate. The L-shaped prefabricated vertical plate comprises a vertical plate body, a first wing plate and a second wing plate located at two ends, a first mortise eye is arranged on the first wing plate, and a second mortise eye corresponding to the first mortise eye is arranged on the second wing plate. Adjacent two L-shaped prefabricated vertical plates are fastened and connected through a bolt assembly arranged in the first mortise eye and the second mortise eye, and a cavity structure is formed between the first wing plate and the second wing plate, and the cavity is filled with an anti-seepage material. The L-shaped prefabricated vertical plate is provided with a reinforcing bar insertion hole at the bottom, the reinforcing bars in the cast-in-place bottom plate are inserted into the reinforcing bar insertion holes in the L-shaped prefabricated vertical plates on the two sides, and the pouring height of the concrete of the cast-in-place bottom plate is submerged at the bottom of the L-shaped prefabricated vertical plate to increase the seepage length. The application adopts the structure of 'bolt connection + cavity anti-seepage + cast-in-place bottom plate submerging vertical plate', has the advantages of reliable connection, excellent anti-seepage performance, convenient construction, environmental friendliness and the like, and can be widely applied to water-saving reconstruction of irrigation areas and high-standard farmland water delivery channel construction projects.

Description

Technical Field

[0001] This invention relates to the technical field of agricultural water conservancy engineering and farmland irrigation facility construction, specifically to a prefabricated canal component and its construction method. Background Technology

[0002] Waterworks are an important means of diverting water from rivers, lakes, and reservoirs for agricultural irrigation, power generation, industrial and domestic use, and are one of the key infrastructure projects supporting national economic and social development. Most of the existing irrigation canals were built in the 1960s and 1970s. Due to various reasons such as the technology and maintenance management level at that time, water leakage in water conveyance canals accounts for 30% to 50% of the total water conveyance, and canal leakage has become a significant loss in the irrigation water conveyance process.

[0003] Currently, canal construction mainly employs two methods: cast-in-place and precast methods, such as:

[0004] Patent application CN113718714A discloses a method for constructing a monolithically cast concrete channel. This method involves forming a cavity using inner and outer formwork. After the formwork is installed, concrete is poured. The concrete enters the formwork through the first cavity between the inner and outer formwork. The concrete is then spread across the bottom slab of the channel foundation through the suspended structure between the inner formwork and the channel excavation edge, thus achieving integrated construction of the concrete channel.

[0005] Patent application CN112267433A discloses a modular water conveyance channel and its construction method. The channel components are provided with male connectors and female connectors. The male connectors and female connectors in two adjacent channel components cooperate to connect multiple channel components end to end to form a channel.

[0006] In the process of high-standard farmland construction and irrigation area modernization, the above methods have improved the technical level of canal construction to a certain extent, but there are still many defects. Among them, the cast-in-place method is greatly affected by the climate and has a long maintenance cycle, making it difficult to complete large-scale construction within the limited time window of winter and spring off-season. In addition, the cast-in-place construction site involves a lot of wet work, which causes greater pollution to the farmland environment.

[0007] Precast components have significant advantages in shortening the construction period and improving efficiency, but they also have problems such as poor seepage prevention and poor construction quality.

[0008] Therefore, there is an urgent need for a channel construction technology that can be quickly assembled without delaying the farming season, adapt to complex farmland foundations, and has excellent seepage prevention performance. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, this invention proposes a prefabricated channel component combining assembly and cast-in-place construction and its construction method. This addresses technical problems such as unstable channel structure and easy leakage at joints in existing technologies, reduces the difficulty of the project and the number of engineering steps, and achieves a green and environmentally friendly construction environment.

[0010] To achieve the above objectives, the present invention employs the following technical means:

[0011] A precast channel component combining assembly and cast-in-place construction, comprising:

[0012] Multiple L-shaped prefabricated vertical slabs arranged opposite each other;

[0013] And the cast-in-place base slab located between the two L-shaped precast vertical slabs;

[0014] The L-shaped prefabricated vertical slab includes a slab body, a first wing plate and a second wing plate located at both ends of the slab body;

[0015] The first wing plate is provided with a first mortise, and the second wing plate is provided with a second mortise corresponding to the position of the first mortise;

[0016] Adjacent L-shaped precast vertical slabs are fastened together by bolt assemblies passing through the first mortise and the second mortise.

[0017] A closed or semi-closed cavity structure is formed between the first wing plate and the second wing plate, and the cavity structure is filled with a waterproof material.

[0018] As a further preferred embodiment of the above-mentioned channel prefabricated component technical solution of the present invention, a first groove is provided on the inner side of the first wing plate, and a second groove is provided on the side of the second wing plate opposite to the first groove. The first groove and the second groove are joined together to form the cavity after two adjacent L-shaped prefabricated upright plates are spliced ​​together.

[0019] As a further preferred embodiment of the above-mentioned channel prefabricated component technical solution of the present invention, the bottom of the L-shaped prefabricated vertical slab is provided with a bar insertion hole, and the cast-in-place base slab is provided with a reinforcing bar, the two ends of which are respectively inserted into the bar insertion holes of the L-shaped prefabricated vertical slabs on both sides.

[0020] As a further preferred embodiment of the above-mentioned precast channel component technical solution of the present invention, the concrete pouring height of the cast-in-place base slab submerges the bottom of the L-shaped precast vertical slab by a certain height to increase the seepage path length.

[0021] As a further preferred embodiment of the above-mentioned channel prefabricated component technical solution of the present invention, the first mortise and the second mortise are through holes or blind holes, and the bolt assembly includes a bolt rod and a nut. The bolt rod passes through the first mortise and the second mortise and is locked by the nut.

[0022] As a further preferred embodiment of the above-mentioned channel prefabricated component technical solution of the present invention, the seepage prevention material is grouting material or pre-embedded water-stop strip.

[0023] As a further preferred embodiment of the above-mentioned channel prefabricated component technical solution of the present invention, the body of the L-shaped prefabricated vertical slab is perpendicular or inclined to the horizontal plane to adapt to channels with different cross-sectional shapes.

[0024] This invention further discloses a construction method based on the assembled and cast-in-place combined precast channel component, comprising the following steps:

[0025] S1: Construction preparation, cleaning and leveling the canal foundation, and inspecting L-shaped precast vertical slab components;

[0026] S2: Multiple L-shaped precast vertical slabs are placed opposite each other on both sides of the channel foundation and temporarily supported;

[0027] S3: Securely connect the first and second wing plates of two adjacent L-shaped precast vertical slabs using a bolt assembly;

[0028] S4: Insert reinforcing bars into the insertion holes of the L-shaped precast vertical slabs on both sides, and pour the bottom concrete of the channel to form a cast-in-place bottom slab;

[0029] S5: After the cast-in-place base slab reaches its strength, inject waterproof material or embed water-stop strips into the cavity structure between adjacent L-shaped precast vertical slabs.

[0030] S6: Inspect all connection points and complete the channel construction.

[0031] As a further preferred embodiment of the above-mentioned construction method of the present invention, in step S4, the concrete pouring height of the cast-in-place base slab submerges the bottom of the L-shaped precast vertical slab by 5-10cm.

[0032] As a further preferred embodiment of the above-mentioned construction method of the present invention, in step S5, the seepage prevention material is an inorganic cementitious agent based on iron and steel metallurgical slag, and the grouting pressure is 0.2-0.5 MPa.

[0033] Compared with existing technologies, it has the following advantages:

[0034] 1. Reliable connection and high structural stability

[0035] This invention employs bolt assemblies that pass through corresponding mortises on the first and second flanges for secure connection. Compared to traditional mortise and tenon joints, bolted connections offer higher connection strength and reliability, effectively resisting lateral earth pressure, water pressure, and vibration loads generated by agricultural machinery operations that the channel may experience during use. Furthermore, bolted connections allow for fine-tuning during assembly, ensuring alignment accuracy between adjacent L-shaped prefabricated vertical slabs and avoiding installation difficulties or structural hazards caused by dimensional deviations in prefabricated components.

[0036] 2. Double anti-seepage structure, excellent sealing performance

[0037] This invention creates a closed cavity structure between the flanges of adjacent L-shaped precast vertical slabs. This cavity can be filled with anti-seepage material after assembly by grouting or pre-embedding water-stop strips, forming the first anti-seepage barrier. Simultaneously, the cast-in-place base slab submerges the bottom of the L-shaped precast vertical slabs to a certain height during pouring, increasing the seepage path length of water along the joint between the vertical slab and the base slab, forming the second anti-seepage barrier. This dual design of "cavity anti-seepage + submerged base slab" is significantly superior to the single anti-seepage method in comparative document 1, which relies solely on reserved grouting grooves and water-stop strips. It can effectively prevent joint leakage during channel operation and improve the water utilization coefficient of the canal system.

[0038] 3. Convenient construction, short construction period, and minimal environmental impact.

[0039] The L-shaped precast vertical slab of this invention is prefabricated in a factory, requiring only bolt assembly and partial concrete pouring on site. This significantly reduces on-site wet work and avoids the formwork erection and long-term curing processes required in traditional cast-in-place construction. Compared to the cumbersome steps in prior art document 1, which require inserting columns before grouting, the bolt connection of this invention allows for further construction without waiting for the grout to solidify, significantly shortening the construction cycle. This is particularly suitable for the rapid construction needs during the winter and spring off-seasons. Furthermore, there is no large-scale concrete mixing or waste slurry discharge on site, minimizing the impact on the farmland ecosystem and meeting the requirements of green construction.

[0040] 4. Highly adaptable, capable of meeting various cross-sectional requirements.

[0041] The L-shaped prefabricated vertical slab of this invention is not limited to vertical installation; its slab body can be tilted at any angle to the horizontal plane according to actual needs, thereby adapting to various channel cross-sections such as rectangular, trapezoidal, and U-shaped, and meeting different terrain conditions and irrigation flow requirements. In contrast, the L-shaped prefabricated component in prior art document 1 is only a right-angled form, with relatively limited adaptability. This invention provides more flexible design options for farmland water conservancy projects.

[0042] 5. Good durability and low maintenance cost.

[0043] The structural design, combining bolted connections with cavity grouting, provides high integrity and durability to the joints between precast vertical slabs, effectively resisting deformation and damage caused by uneven foundation settlement, frost heave, and other adverse factors. Simultaneously, the reliable connection between the cast-in-place base slab and the precast vertical slabs avoids common problems in traditional channels, such as detachment of the base slab from the sidewalls and joint cracking, significantly reducing the frequency and cost of subsequent channel maintenance.

[0044] In summary, this invention has achieved significant technological advancements in terms of structural stability, seepage prevention performance, construction efficiency, environmental friendliness, and engineering adaptability, and has extremely high practical value and promising prospects for promotion. Attached Figure Description

[0045] Figure 1 This is a single-part diagram of the "L"-shaped prefabricated vertical slab in Embodiment 1 of the present invention;

[0046] Figure 2 This is a front view of the "L"-shaped prefabricated vertical slab assembled in two parts in Embodiment 1 of the present invention;

[0047] Figure 3 This is a back view of the "L"-shaped prefabricated vertical slab assembled in two parts in Embodiment 1 of the present invention;

[0048] Figure 4 This is a schematic diagram of a section of an irrigation canal according to the present invention;

[0049] Figure 5 This is the stress diagram of finite element analysis under working condition 1 of this invention;

[0050] Figure 6 This is the stress diagram of finite element analysis under working condition 2 of this invention;

[0051] Figure 7 This is the normal water level potential diagram for channel operating condition 2 of the present invention;

[0052] In the figure: 1 is the first wing plate; 2 is the second wing plate; 301 is the first mortise; 302 is the second mortise; 401 is the first groove; 402 is the second groove; 4 is the cavity structure; 5 is the insertion hole for the reinforcing bar. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] Please see Figure 1-5 ,

[0055] A precast channel component combining assembly and cast-in-place construction, comprising:

[0056] Multiple L-shaped prefabricated vertical slabs arranged opposite each other;

[0057] And the cast-in-place base slab located between the two L-shaped precast vertical slabs;

[0058] The L-shaped prefabricated vertical slab includes a slab body, a first wing plate 1 and a second wing plate 2 located at both ends of the slab body;

[0059] The first wing plate 1 is provided with a first mortise 301, and the second wing plate 2 is provided with a second mortise 302 corresponding to the position of the first mortise;

[0060] Adjacent L-shaped precast vertical slabs are fastened together by bolt assemblies passing through the first mortise 301 and the second mortise 302;

[0061] A closed or semi-closed cavity structure 4 is formed between the first wing plate 1 and the second wing plate 2, and the cavity structure 4 is filled with a waterproof material.

[0062] This invention employs bolt assemblies that pass through corresponding mortises on the first wing plate 1 and the second wing plate 2 for secure connection. Compared to traditional mortise and tenon joints, bolted connections offer higher connection strength and reliability, effectively resisting lateral earth pressure, water pressure, and vibration loads generated by agricultural machinery operations that the channel may experience during use. Furthermore, bolted connections allow for fine-tuning during assembly, ensuring alignment accuracy between adjacent L-shaped prefabricated vertical slabs and avoiding installation difficulties or structural hazards caused by dimensional deviations in prefabricated components.

[0063] As a further preferred embodiment of the above-mentioned channel prefabricated component technical solution of the present invention, a first groove is provided on the inner side of the first wing plate, and a second groove is provided on the side of the second wing plate opposite to the first groove. The first groove and the second groove are joined together to form the cavity after two adjacent L-shaped prefabricated upright plates are spliced ​​together.

[0064] As a further preferred embodiment of the precast channel component technical solution of the present invention, the bottom of the L-shaped precast vertical slab is provided with reinforcing bar holes, and reinforcing bars are provided in the cast-in-place base slab. The two ends of the reinforcing bars are respectively inserted into the reinforcing bar holes of the L-shaped precast vertical slabs on both sides. The concrete pouring height of the cast-in-place base slab submerges the bottom of the L-shaped precast vertical slab by a certain height to increase the seepage path length. The present invention forms a closed cavity structure between the flanges of adjacent L-shaped precast vertical slabs. This cavity structure can be filled with anti-seepage material by grouting or pre-embedded water-stop strips after assembly, forming the first anti-seepage barrier. At the same time, the cast-in-place base slab submerges the bottom of the L-shaped precast vertical slab by a certain height during pouring, increasing the seepage path length of water along the joint between the vertical slab and the base slab, forming the second anti-seepage barrier. This dual design of "cavity anti-seepage + submerged base slab" is significantly better than the single anti-seepage method of pre-reserved grouting grooves and water-stop strips in the prior art document 1, which can effectively prevent joint leakage during channel operation and improve the water utilization coefficient of the channel system.

[0065] As a further preferred embodiment of the above-mentioned channel prefabricated component technical solution of the present invention, the first mortise and the second mortise are through holes or blind holes, and the bolt assembly includes a bolt rod and a nut. The bolt rod passes through the first mortise and the second mortise and is locked by the nut.

[0066] As a further preferred embodiment of the above-mentioned channel prefabricated component technical solution of the present invention, the seepage prevention material is grouting material or pre-embedded water-stop strip.

[0067] As a further preferred embodiment of the prefabricated channel component technical solution of the present invention, the L-shaped prefabricated vertical slab has its body perpendicular or inclined to the horizontal plane to adapt to channels with different cross-sectional shapes. The L-shaped prefabricated vertical slab of the present invention is not limited to a vertical arrangement; its body can be inclined at any angle to the horizontal plane according to actual needs, thereby adapting to various channel cross-sectional forms such as rectangular, trapezoidal, and U-shaped channels, and meeting different terrain conditions and irrigation flow requirements. In contrast, the L-shaped prefabricated component in prior art document 1 is only a right-angled form, with relatively limited adaptability. The present invention provides more flexible design options for farmland water conservancy projects.

[0068] A construction method for a precast channel component combining assembly and cast-in-place construction, based on the aforementioned precast channel component combining assembly and cast-in-place construction, includes the following steps.

[0069] S1: Construction preparation, cleaning and leveling the canal foundation, and inspecting L-shaped precast vertical slab components;

[0070] S2: Multiple L-shaped precast vertical slabs are placed opposite each other on both sides of the channel foundation and temporarily supported;

[0071] S3: Securely connect the first and second wing plates of two adjacent L-shaped precast vertical slabs using a bolt assembly;

[0072] S4: Insert reinforcing bars into the insertion holes of the L-shaped precast vertical slabs on both sides, and pour the bottom concrete of the channel to form a cast-in-place bottom slab;

[0073] S5: After the cast-in-place base slab reaches its strength, inject waterproof material or embed water-stop strips into the cavity structure between adjacent L-shaped precast vertical slabs.

[0074] S6: Inspect all connection points and complete the channel construction.

[0075] As a further preferred embodiment of the above-mentioned construction method of the present invention, in step S4, the concrete pouring height of the cast-in-place base slab submerges the bottom of the L-shaped precast vertical slab by 5-10cm.

[0076] As a further preferred embodiment of the above-mentioned construction method of the present invention, in step S5, the seepage prevention material is an inorganic cementitious agent based on iron and steel metallurgical slag, and the grouting pressure is 0.2-0.5 MPa.

[0077] To verify the stability of the structure, finite element analysis was used. The structural unit consisted of a rectangular channel assembled from two prefabricated structures. The channel was 4m long and 3.5m high, with a water level of 3.5m when full. The outer backfill was 3.5m thick, and the concrete thickness was 0.2m. The L-shaped prefabricated structure was entirely constructed using steel metallurgical slag-based cementitious concrete. This material has a compressive strength of 32.4 MPa, a tensile strength of 2.64 MPa, and a seepage prevention grade of P12.

[0078] The main considerations are two operating conditions: with water and without water.

[0079] Condition 1: Considering the earth pressure outside the canal, there is no water inside the canal;

[0080] Working condition 2: Considering the earth pressure outside the canal, the canal is full of water.

[0081] The calculation results for the two working conditions are as follows: Figure 4 , Figure 5 The channel seepage calculation under condition 2 is as follows: Figure 6 .

[0082] The calculation results show that under condition 1, the maximum tensile stress is 0.52 MPa and the maximum compressive stress is 0.15 MPa; under condition 2, the maximum tensile stress is 0.21 MPa and the maximum compressive stress is 0.06 MPa. Under both conditions, the tensile and compressive stresses within the channel structure do not reach the material's tensile and compressive strength limits, indicating that the structure can operate safely under the design conditions. Under condition 1 (no water) compared to condition 2 (full water), the channel experiences greater tensile stress, indicating that the stress conditions under the sole action of external earth pressure are more unfavorable, but still within a safe range. The stress distribution in the channel is relatively uniform under both conditions, with no excessive stress concentration, proving that the structural design has good stability and adaptability. Figure 6 The calculation results show that, under working condition 2, the seepage potential is relatively large on both sides of the bottom plate of the channel. This is mainly because this is where the cast-in-place bottom plate and the side wall are joined. However, the water level potential on the outside of the channel is 0, indicating that the channel has good seepage prevention performance and no water seepage occurs at the contact surface.

[0083] This invention provides a precast channel component combining assembly and cast-in-place construction, and its construction method. Many methods and approaches exist for implementing this technical solution; the above description is merely a preferred embodiment of the invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications should also be considered within the scope of protection of this invention. All components not explicitly stated in this embodiment can be implemented using existing technologies.

Claims

1. A precast channel component combining assembly and cast-in-place construction, characterized in that, include: Multiple L-shaped prefabricated vertical slabs arranged opposite each other; And the cast-in-place base slab located between the two L-shaped precast vertical slabs; The L-shaped prefabricated vertical slab includes a slab body, a first wing plate and a second wing plate located at both ends of the slab body; The first wing plate is provided with a first mortise, and the second wing plate is provided with a second mortise corresponding to the position of the first mortise; Adjacent L-shaped precast vertical slabs are fastened together by bolt assemblies passing through the first mortise and the second mortise. A closed cavity structure is formed between the first wing plate and the second wing plate, and the cavity is filled with a waterproof material.

2. The precast channel component combining assembly and cast-in-place construction according to claim 1, characterized in that, The first wing plate has a first groove on its inner side, and the second wing plate has a second groove on the side opposite to the first groove. The first groove and the second groove are joined together to form the cavity after two adjacent L-shaped prefabricated vertical plates are spliced ​​together.

3. The prefabricated channel component combining assembly and cast-in-place construction according to claim 1, characterized in that, The bottom of the L-shaped precast vertical slab is provided with reinforcing bar holes, and the cast-in-place base slab is provided with reinforcing bars. The two ends of the reinforcing bars are respectively inserted into the reinforcing bar holes of the L-shaped precast vertical slabs on both sides.

4. A prefabricated channel component combining assembly and cast-in-place construction according to claim 1, characterized in that, The concrete pouring height of the cast-in-place base slab submerges the bottom of the L-shaped precast vertical slab by a certain height to increase the seepage path length.

5. A prefabricated channel component combining assembly and cast-in-place construction according to claim 1, characterized in that, The first mortise and the second mortise are through holes. The bolt assembly includes a bolt shank and a nut. The bolt shank passes through the first mortise and the second mortise and is locked in place by the nut.

6. A prefabricated channel component combining assembly and cast-in-place construction according to claim 1, characterized in that, The seepage-proof material is either grouting material or embedded water-stop strips.

7. A prefabricated channel component combining assembly and cast-in-place construction according to claim 1, characterized in that, The L-shaped prefabricated vertical slab has a vertical or inclined angle to the horizontal plane to adapt to channels with different cross-sectional shapes.

8. The construction method for prefabricated channel components combining assembly and cast-in-place construction according to any one of claims 1 to 7, characterized in that, Includes the following steps: S1: Construction preparation, cleaning and leveling the canal foundation, and inspecting L-shaped precast vertical slab components; S2: Multiple L-shaped precast vertical slabs are placed opposite each other on both sides of the channel foundation and temporarily supported; S3: Securely connect the first and second wing plates of two adjacent L-shaped precast vertical slabs using a bolt assembly; S4: Insert reinforcing bars into the insertion holes of the L-shaped precast vertical slabs on both sides, and pour the bottom concrete of the channel to form a cast-in-place bottom slab; S5: After the cast-in-place base slab reaches its strength, inject waterproof material or embed water-stop strips into the cavity structure between adjacent L-shaped precast vertical slabs. S6: Inspect all connection points and complete the channel construction.

9. The construction method for prefabricated channel components combining assembly and cast-in-place construction according to claim 8, characterized in that, In step S4, the concrete pouring height of the cast-in-place base slab submerges the bottom of the L-shaped precast vertical slab by 5-10cm.

10. The construction method for prefabricated channel components combining assembly and cast-in-place construction according to claim 8, characterized in that, In step S5, the seepage prevention material is an inorganic cementitious agent based on iron and steel metallurgical slag, and the grouting pressure is 0.2-0.5 MPa.

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